Low friction reciprocating pump and method of operation

Abstract

The low-friction reciprocating pump and working method of the present application, the contact surface of the cylinder and the plug body includes at least one plane, and the plane is provided with an open slit at a certain angle with the moving direction of the plug body; at least one cylindrical roller is rotatably embedded in the solid interior of the cylinder / plug body, the rotating shaft direction of the roller is perpendicular to the moving direction of the plug body, and the contact curved surface closely abuts and protrudes the open slit and abuts against the plug body / cylinder. The present application changes the sliding friction generated by the complete abutment of the plug body and the inner wall surface of the cylinder in the prior art into the rolling friction generated by the rolling abutment between the plug body / cylinder and the roller by setting the open slit and the roller; at the same time, because the contact curved surface is away from the plane by a certain height, there is an included angle between the plug body and the inner wall surface of the cylinder, so there is a gap, which also helps to reduce the sliding friction, so as to reduce the heating and energy consumption problems in the operation process of the reciprocating pump.

Description

Technical Field

[0001] This invention belongs to the field of fluid transport technology, specifically relating to a low-friction reciprocating pump and its working method. Background Technology

[0002] In the field of fluid transport, including both liquids and gases, many processes involve driving fluids forward with pressure, typically using a pump to pressurize the fluid. Common pumps include impeller pumps such as centrifugal pumps and positive displacement pumps such as reciprocating pumps. Impeller pumps use rotating blades to continuously pressurize and drive the fluid forward. They generally have a large flow rate but a relatively low pressure increase, making them more suitable for outputting high-flow-rate, low-pressure fluids, such as fans. Reciprocating pumps, on the other hand, utilize the reciprocating motion of a piston or plunger within a cylinder to change the volume of the sealed space inside the cylinder, thereby changing the pressure of the fluid inside the cylinder. Combined with the opening and closing of a check valve under pressure, the fluid is drawn in, pressurized, and then discharged. This allows for higher pressure requirements but a relatively lower flow rate, making them more suitable for applications requiring high-pressure, low-volume liquids, such as in water / oil jet pumps. During operation, the high pressure in the fluid is converted into high speed, which then attracts and drives nearby low-speed fluids forward during the jet, thus increasing the flow rate. Since liquids are incompressible, when a plug is used to compress and transport liquids, the liquid can be subjected to very high pressure, thereby achieving a very high head.

[0003] However, for reciprocating pumps, because the plunger or piston needs to be in close contact with the inner wall of the cylinder and move back and forth, significant sliding friction is generated. Furthermore, because the fluid inside the cylinder needs to be pressurized, the sealing between the plunger and the cylinder requires a high degree of tightness, further increasing sliding friction. This high sliding friction increases resistance to movement, resulting in unnecessary energy consumption. On the other hand, frictional heat causes the plunger and cylinder to heat up rapidly, leading to thermal expansion and contraction, further increasing the pressure between the plunger and cylinder, which in turn increases friction, creating a positive feedback loop. Moreover, if there is uneven internal structure, resulting in uneven expansion and deformation of the plunger and / or cylinder, the fit / sealing between the plunger and cylinder will decrease, affecting the pressurization effect on the fluid inside the cylinder. At the same time, high temperatures obviously also affect the service life of the plunger and cylinder.

[0004] Therefore, existing technologies need further improvement and enhancement. Summary of the Invention

[0005] In view of the above-mentioned defects of the prior art, the purpose of the present invention is to provide a low-friction reciprocating pump and its working method, so as to solve the technical defects of the prior art reciprocating pump, which are increased energy consumption, decreased sealing and pressurization effect and reduced service life due to excessive sliding friction between the piston and the cylinder, resulting in frictional heat generation.

[0006] This invention discloses a low-friction reciprocating pump, comprising:

[0007] A cylindrical cylinder is connected to a sealed cavity, and a plug is provided in the cylinder that can seal the cylinder and reciprocate along the length of the cylinder;

[0008] The sealed cavity is connected to the suction pipe via an inlet check valve for drawing in the fluid to be driven from the outside; and is connected to the discharge pipe via an outlet check valve for discharging the fluid to be driven.

[0009] The contact surface between the cylinder and the plug includes at least one plane, and at least one opening slit at a certain angle to the direction of movement of the plug is opened on the plane;

[0010] At least one cylindrical roller is rotatably embedded inside the cylinder / plug body. The rotation axis of the roller is perpendicular to the movement direction of the plug body. The contact surface of the roller is in close contact with and protrudes from the opening slot, abutting against the plug body / cylinder.

[0011] The low-friction reciprocating pump of the present invention includes a drive unit connected to a sealed cavity. The drive unit includes a cylinder and a plug that reciprocates within the cylinder. The contact surface between the cylinder and the plug includes at least one plane. At least one opening slit is formed on the plane at a certain angle to the direction of movement of the plug. At least one cylindrical roller is rotatably embedded inside the solid of the cylinder / plug. The rotation axis of the roller is perpendicular to the direction of movement of the plug. A portion of the curved surface of the roller is in close contact with and protrudes from the opening slit, and then abuts against the plug / cylinder. This invention adds an opening between the plug and the cylinder, and sets a roller that can roll in place within the solid body of the plug or cylinder. A portion of the roller's curved surface protrudes from the opening to form a contact surface, abutting against the cylinder or plug. The roller is driven to roll by the reciprocating translation of the plug along the inner wall of the cylinder. This changes the sliding friction generated by the complete contact between the plug and the inner wall of the cylinder in the prior art to rolling contact between the plug or cylinder and the roller, generating rolling friction. At the same time, because the contact surface is at a certain height above the plane, there is an angle between the plug and the inner wall of the cylinder, thus creating a gap. This also helps to reduce the sliding friction between the plug and the cylinder, thereby reducing the heat generation and energy consumption during the operation of the reciprocating pump.

[0012] Preferably, the roller is rotatably fixed inside the cylinder / plug body via elastic supports at both ends. The elastic supports keep the roller pushed towards the opening, ensuring that the contact surface remains in close contact with and protrudes from the opening. By providing elastic supports, especially pre-stretched elastic supports, and positioning the roller at an acute angle towards the opening, the elastic force can pull the roller close to the opening, ensuring that the contact surface is tightly against the inner wall of the plug or cylinder. Driven by the reciprocating movement of the plug, the roller rolls in place, generating rolling friction, thus changing the large sliding friction between the plug and cylinder into smaller rolling friction.

[0013] In one embodiment, the cross-sections of the cylinder and the plug are matching polygons, and at least one side of the cylinder and / or the plug is provided with at least one opening and at least one roller. The polygonal cylindrical cylinder and plug can have the opening and roller provided on each side, thus changing all sliding friction when the planes are in contact to rolling friction.

[0014] In one embodiment, along the length of the cylinder, the inner wall surface of the cylinder is provided with a set of openings, and the distance between two adjacent openings is less than the thickness of the plug. This ensures that at any position where the plug moves, at least one contact surface abuts against the plug, and the movement of the plug drives the roller to rotate, generating rotational friction.

[0015] Preferably, along the length of the cylinder, the inner wall surface of the cylinder is provided with a set of openings, and the distance between three adjacent openings is less than the thickness of the plug. This ensures that during the movement of the plug, at least two contact surfaces always abut against the plug, guaranteeing the straight-line movement of the plug and preventing deviation or vibration.

[0016] In another embodiment, the plug body has at least two openings along its thickness on the plane, and each opening is provided with a roller. Providing openings and rollers on the plug body, regardless of the plug body's thickness, typically only requires two openings distributed along the thickness direction, especially two parallel ones, which helps reduce production costs.

[0017] In one embodiment, a roller cavity is further included, which is disposed inside the solid body of the cylinder / plug, and the roller is rotatably disposed within the roller cavity. Providing a roller cavity helps reduce sliding friction between the roller and the solid body.

[0018] More preferably, the roller cavity is provided with a lubricating fluid that is immiscible with the fluid to be driven. Adding lubricating fluid further reduces sliding friction between the roller and the solid body and ensures cooling. Simultaneously, the lubricating fluid also prevents the fluid to be driven from entering the roller cavity.

[0019] Preferably, an elastic membrane is further included, disposed between the plug and the sealing cavity, to completely separate the sealing cavity. The elastic membrane completely prevents the fluid to be driven from contacting the plug and the opening, helping to maintain the pressure within the sealing cavity.

[0020] The present invention also discloses a method for operating the low-friction reciprocating pump, comprising the following steps:

[0021] a. The drive rod drives the piston to reciprocate along the inner wall of the cylinder.

[0022] b. The plug abuts against and rubs against the contact surface during movement;

[0023] c. The contact surface causes the roller to roll in place;

[0024] d. The plug moves, changing the volume of the sealing cavity;

[0025] e. The inlet check valve / outlet check valve opens and closes independently as the pressure in the sealed cavity changes;

[0026] f. The fluid to be driven is drawn in / discharged into the sealed cavity.

[0027] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the low-friction reciprocating pump of the present invention;

[0029] Figure 2 This is a schematic cross-sectional view of the drive section in the low-friction reciprocating pump of the present invention;

[0030] Figure 3 This is a schematic diagram of the installation structure of the drum in the low-friction reciprocating pump of the present invention;

[0031] Figure 4 This is a schematic diagram of the second embodiment of the drive unit of the low-friction reciprocating pump of the present invention;

[0032] In the diagram, 100-plug body, 120-drive rod, 200-cylinder, 210-suction pipe, 211-inlet check valve, 220-discharge pipe, 221-outlet check valve, 250-sealing cavity, 300-roller, 310-contact surface, 320-elastic support rod, 350-opening slit, 360-roller cavity. Implementation

[0033] This invention provides a low-friction reciprocating pump and its operating method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0034] The present invention provides a low-friction reciprocating pump, the overall structure of which is similar to that of existing reciprocating pumps, such as... Figure 1 As shown, each includes a drive unit connected to a sealed cavity 250. The sealed cavity 250 is connected to a suction pipe 210 via an inlet check valve 211 for drawing in the fluid to be driven from the outside; and to a discharge pipe 220 via an outlet check valve 221 for discharging the fluid to be driven. The drive unit includes a cylindrical cylinder 200 that connects to or naturally extends into the sealed cavity 250. A plug 100 is provided within the cylinder 200 to seal it. Driven by a drive rod 120, the plug 100 can reciprocate along the length of the cylinder 200. Depending on the pressure requirements, the plug 100 can be a thin piston or a thick plunger. The plug 200 divides the sealed cavity 250 into a closed space.

[0035] Specifically, when the plug 100 is driven to move toward the sealing cavity 250, the volume of the sealing cavity 250 is compressed, the fluid to be driven in the sealing cavity 250 is under positive pressure, the inlet check valve 211 is closed, the outlet check valve 221 is opened, and the fluid to be driven is forced out from the discharge pipe 220; while when the plug 100 is driven to move away from the sealing cavity 250, the volume of the sealing cavity 250 is expanded, the fluid to be driven in the sealing cavity 250 is under negative pressure, the outlet check valve 221 is closed, the inlet check valve 211 is opened, and new fluid to be driven enters the sealing cavity 250 from the suction pipe 210.

[0036] The low-friction reciprocating pump of the present invention improves the drive unit to reduce the friction between the piston 100 and the cylinder 200. Specifically, the contact surface between the cylinder 200 and the piston 100 is changed, and at least one plane is provided. That is, the curved surfaces of the cylindrical piston and cylinder of the existing reciprocating pump are improved, and at least a portion of the curved surface is changed to a plane. Or as... Figure 2As shown in the cross-sectional schematic diagram, the plug body 100 and cylinder 200 are directly constructed using mutually matching and tightly fitted polygonal cylinders. At least one opening slit is formed on the plane. At least one opening slit 350 is formed on the plane at a certain angle to the moving direction of the plug body 100. The opening slit 350 is preferably perpendicular to the length direction of the cylinder 200, i.e., the moving direction of the plug body 100. Simultaneously, behind the opening slit 350, i.e., within the solid body of the cylinder 200 or the plug body 100, one or a group of cylindrical rollers 300 connected end-to-end are embedded. The diameter of the roller 300 is greater than the opening width of the opening slit 350, and the total length of all the rollers 300 is equal to the opening length of the opening slit 350. Thus, when the roller 300 is in close contact with the opening slit 350, it can close the opening slit 350, preventing the fluid to be driven from entering the opening slit 350.

[0037] Specifically, such as Figure 3 As shown, the roller 300 is rotatably embedded in the solid of the cylinder 200 / plug 100, and the rotation axis of the roller 300 is perpendicular to the movement direction of the plug 100. When the opening slit 350 is perpendicular to the movement direction of the plug 100, the rotation axis of the roller 300 is parallel to the opening slit 350. A portion of the curved surface of the roller 300 closely abuts and protrudes from the opening slit 350, thereby abutting against the plug 100 / cylinder 200 to form a contact surface 310. Thus, when the plug 100 reciprocates within the cylinder 200, the contact surface 310, on the one hand, tightly abuts against the plug 100 / cylinder 200, ensuring a seal; on the other hand, because of this tight abutment, the roller 300 will rotate under the drive of friction, changing the sliding friction into rotational friction, thereby greatly reducing the magnitude of the friction between the plug 100 and the cylinder 200.

[0038] To ensure that the roller 300 remains tightly against the opening slit 350 and that the contact surface 310 always protrudes from the opening slit 350, in a preferred embodiment, the roller 300 is rotatable within the solid body of the cylinder 200 / plug 100 via elastic supports 320 at both ends. The elastic supports 320 can be partially stretched springs or elastic rods, extending from the roller 300 at an acute angle towards the opening slit 350. After installation, the rebound force will maintain the roller 300's tendency to move towards the opening slit 350, thereby ensuring that the roller 300 remains tightly against the opening slit 350 and that the contact surface 310 protrudes from the opening slit 350.

[0039] Considering that the pressure in the sealed cavity 250 is usually high, installing the roller 300 might cause leakage of the fluid to be driven. Also, considering that when the roller 300 rotates within the solid body of the plug body 100 / cylinder 200, sliding friction will also exist between the curved surface and the solid body; therefore, a hollow roller cavity 360 can be first opened within the solid body of the plug body 100 / cylinder 200. For example... Figure 3 As shown, the size of the roller cavity 360 is larger than the size of the roller 300. This prevents the roller 300 from contacting the inner wall of the roller cavity 360 during rotation, thus avoiding additional friction. The roller cavity 360 can even be filled with lubricating fluid, which lubricates the roller 300 and helps seal the sealing cavity 250. Simultaneously, because the contact surface 310 protrudes a certain height from the opening slit 350, a gap exists between the plug 100 and the inner wall of the cylinder 200, allowing the lubricating fluid to enter this gap and further reduce the sliding friction between them. Of course, to prevent the lubricating fluid from entering the sealing cavity and contaminating the fluid to be driven, a component immiscible with the fluid can be used. For example, if the fluid to be driven is water-based, the lubricating fluid can be oil-based, or vice versa.

[0040] To ensure the sealing performance of the sealing cavity 250, an elastic membrane can be provided between the plug body 100 and the sealing cavity 250 to completely separate the fluid to be driven in the sealing cavity 250 from the plug body 100. Specifically, when the plug 100 moves toward the sealing cavity 250, it pushes the elastic diaphragm, compressing the volume of the sealing cavity 250. The pressure of the fluid to be driven in the sealing cavity 250 increases, the inlet check valve 211 closes, the outlet check valve 221 opens, and the fluid to be driven is forced out from the discharge pipe 220. When the plug 100 moves away from the sealing cavity 250, the elastic diaphragm is released, and the elastic diaphragm rebounds. Or, because the space between the elastic diaphragm and the plug 100 is filled with incompressible lubricating fluid, the negative pressure causes the elastic diaphragm to deform as the plug 100 moves away, expanding the volume of the sealing cavity 250. The fluid to be driven in the sealing cavity 250 becomes negative pressure, the outlet check valve 221 closes, the inlet check valve 211 opens, and new fluid to be driven enters the sealing cavity 250 from the suction pipe 210.

[0041] The opening slit 350 and the roller 300 can be arranged on the plane of the side of the plug body 100 or on the plane of the side of the cylinder 200. Figure 1 An embodiment is shown in which the opening slit 350 and the roller 300 are disposed on the plug body 100. In order to ensure the stability of the plug body 100 in translational movement close to the inner wall surface of the cylinder 200, the opening slit 350 and the roller 300 are preferably configured as at least two sets arranged parallel to each other and along the thickness direction of the plug body 100. This can limit the plug body 100 to reciprocating motion only in a straight line. Figure 4The second embodiment shows a set of openings 350 disposed on the inner wall surface of the cylinder 200. In this case, the openings 350 need to be disposed on the inner wall surface of the cylinder 200 reached by the plug 100 throughout its entire stroke. Preferably, the distance between two adjacent openings 350 is less than the thickness of the plug 100. This ensures that during the movement of the plug 100, at least one contact surface 310 is always in close contact with the plug 100, and the two only experience rolling friction. At the same time, because the contact surface 310 protrudes from the openings 350 by a certain height, this ensures that most of the plug 100 has a certain gap with the inner wall surface of the cylinder 200, rather than being tightly fitted. This also reduces the sliding friction between the plug 100 and the inner wall surface of the cylinder 200. In a preferred embodiment, the distance between three adjacent openings 350 can be set to be less than the thickness of the plug 100. This ensures that at any position during the stroke of the plug 100, the side of the plug simultaneously abuts against two parallel contact surfaces 310. This means that throughout the entire reciprocating translation of the plug 100 along the inner wall of the cylinder 200, it only comes into contact with the roller 300, which can roll in place. Therefore, only rolling friction is generated. Under the same pressure, rolling friction is significantly less than sliding friction, ensuring a low frictional force between the cylinder 200 and the plug 100 while maintaining a seal. Furthermore, since two points define a straight line, and the plug 100 is in close contact with the contact surfaces 310, the reciprocating direction of the plug 100 is fixed. When passing through the openings 350, it will not be disturbed by the protruding contact surfaces 310, thus avoiding lateral vibration, high noise and disturbance, additional heat generation, and wasted energy.

[0042] As can be seen, the working method of the reciprocating pump described in this invention includes the following steps:

[0043] a. The drive rod 120 drives the piston 100 to reciprocate along the inner wall of the cylinder 200;

[0044] b. The plug 100 abuts against and rubs against the contact surface 310 during movement;

[0045] c. The contact surface 310 drives the roller 300 to roll in place;

[0046] d. The plug body 100 moves, changing the volume of the sealing cavity 250;

[0047] e. The inlet check valve 211 and the outlet check valve 221 open and close respectively according to the pressure change in the sealing cavity 250;

[0048] f. The fluid to be driven is drawn in / discharged into the sealed cavity 250.

[0049] In summary, the low-friction reciprocating pump of the present invention adds an opening slit 350 between the plug body 100 and the cylinder 200, and provides a roller 300 that can roll in place within the solid body of the plug body 100 or the cylinder 200. The contact surface 310 of the roller 300 protrudes from the opening slit 350 and abuts against the cylinder 200 or the plug body 100, and is driven to roll by the translation of the plug body 100 along the inner wall of the cylinder 200. This improves upon the prior art where the friction is generated by the movement of the plug body 100 and the inner wall of the cylinder 200. The sliding friction generated by the complete contact of the wall surfaces is changed to rolling contact between the plug 100 or cylinder 200 and the roller 300, generating rolling friction. At the same time, because the contact surface 310 is at a certain height away from the plane, there is an angle between the inner wall surfaces of the plug 100 and the cylinder 200, thus creating a gap. This also helps to reduce the sliding friction between the plug 100 and the cylinder 200 in the prior art, thereby reducing the heat generation and energy consumption problems during the operation of the reciprocating pump.

[0050] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A low-friction reciprocating pump, characterized in that: A cylindrical cylinder is connected to a sealed cavity, and a plug is provided in the cylinder that can seal the cylinder and reciprocate along the length of the cylinder; The sealed cavity is connected to the suction pipe via an inlet check valve for drawing in the fluid to be driven from the outside; and is connected to the discharge pipe via an outlet check valve for discharging the fluid to be driven. The contact surface between the cylinder and the plug includes at least one plane, and at least one opening slit at a certain angle to the direction of movement of the plug is opened on the plane; At least one cylindrical roller is rotatably embedded inside the solid of the cylinder / plug body. The rotation axis of the roller is perpendicular to the movement direction of the plug body. The contact surface of the roller is in close contact with and protrudes from the opening slit, and abuts against the plug body / cylinder body. The roller is fixed inside the cylinder / plug body and can rotate via elastic brackets at both ends. The elastic brackets keep the roller pushed towards the opening, so that the contact surface remains in close contact with and protrudes from the opening.

2. The reciprocating pump according to claim 1, characterized in that, The cylinder and the plug have matching polygonal cross-sections, and at least one side of the cylinder and / or the plug has at least one opening and at least one roller.

3. The reciprocating pump according to claim 1, characterized in that, Along the length of the cylinder, the inner wall surface of the cylinder is provided with a set of openings, and the distance between two adjacent openings is less than the thickness of the plug.

4. The reciprocating pump according to claim 1, characterized in that, Along the length of the cylinder, the inner wall surface of the cylinder is provided with a set of openings, and the distance between three adjacent openings is less than the thickness of the plug.

5. The reciprocating pump according to claim 1, characterized in that, The plug has at least two openings along its thickness on the plane, and each opening is provided with a roller.

6. The reciprocating pump according to claim 1, characterized in that, It also includes a roller cavity, which is disposed inside the solid body of the cylinder / plug body, and the roller is rotatably disposed in the roller cavity.

7. The reciprocating pump according to claim 6, characterized in that, The drum cavity is provided with lubricating fluid, which is immiscible with the fluid to be driven.

8. The reciprocating pump according to claim 1, characterized in that, It also includes an elastic membrane disposed between the plug and the sealing cavity to completely separate the sealing cavity.

9. The method of operating the reciprocating pump according to any one of claims 1 to 8, characterized in that, Including the following steps: a. The drive rod drives the piston to reciprocate along the inner wall of the cylinder. b. The plug abuts against and rubs against the contact surface during movement; c. The contact surface causes the roller to roll in place; d. The plug moves, changing the volume of the sealing cavity; e. The inlet check valve / outlet check valve opens and closes independently as the pressure in the sealed cavity changes; f. The fluid to be driven is drawn in / discharged into the sealed cavity.

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